1. Field of the Invention
The present invention concerns a balloon for illumination purposes inflatable with air. The balloon, at its centre, contains an illumination light source in the form of an electric lamp, and includes a plurality of segments forming meridians, which are mutually interconnected in such a manner that they form an essentially spherical body. The segments are made from a particularly air-impermeable fabric and, at the lower pole of the sphere, a connecting disc is provided so that all segments merge and connect the balloon in a substantially airtight manner with a connecting rod.
2. Discussion of Background Information
Realization and application of balloons of such type suitable for illuminating large open air event areas, such as squares, fields or ski runs, over the last years has become more frequent owing to the advantages offered by this type of illumination set-ups. Among these the ease of setting up of the plant is to be mentioned (where just a supporting rod is to be anchored on the ground, if not —as in the case of application of helium-filled balloons—merely an electric cable is sufficient), as well as the absence of any blinding effects owing to the fact that the light emitted from the balloon surface is diffuse and thus can not cause any blinding effects. This technology thus is ideally suited for setting up temporary illumination plants for large areas without requiring any costly fixed installation.
From practical applications various types of inflatable balloons are known containing a light source inside, which can be subdivided essentially into two categories, namely in balloons filled with a lighter-than-air gas on one hand, which float upward and are to be anchored to the ground merely like a blimp (captive balloon), and in air-filled balloons on the other hand.
In the first category e.g. the balloon HeliMax Powermoon is to be mentioned, made from a material called Levapren by the German Company Noelle Industrielle Umwelttechnik GmbH at Rheinberg and described in the internet under http://www.powermoon.de/ger.php?p=german.
This balloon can be produced with diameters of up to 5.5 m and behaves just like a blimp (captive balloon), which must be anchored to the ground using an array of cables in such a manner that it can not drift off. The helium-filled balloon, proposed for illumination purposes more than a century ago, implies the use of an inert lighter-than-air gas, normally helium, which requirement severely limits applicability. The use of a gas differing from air furthermore implies that the balloon be absolutely impermeable, not permitting any leaking of the balloon-gas into the surrounding air. The material used thus must be absolutely impermeable—which implies that very expensive materials are to be considered—and is not to contain any gas-permeable connecting areas or seams. These requirements render realization of helium-filled balloons extremely difficult and cost-intensive.
The other category of the inflatable balloons is the one of balloons inflatable with air. Balloons of this type according to the state of the art are easier to realize in comparison with the ones described above and handling is less complicated as air always is available in unlimited quantity. Such balloons of course do not float up from the ground but are to be supported on a suitable support rod, via which also the electric supply cable for the illumination and possibly also a pneumatic duct can lead serving for inflating the balloon at the beginning and, if needed, for maintaining the required filling pressure inside the balloon. Design-wise the advantage over helium-filled balloons is seen in that they can be manufactured using ordinary fabrics (such as polyester or nylon), which are of low cost and easily processed, if air-tightness is to be improved, by means of a surface treatment e.g. polyurethane coating, in order to permit realization of cost-efficient fabrics suitable for application in inflatable balloons.
Typical for this kind of balloon is the one produced and marketed under the name of Sunglobe by the company Intercomm srl at 31030 Arcade (Tv). This balloon is made from fabric and consists of a plurality of segments forming meridian lines along which the segments are interconnected in such a manner that an essentially spherical body is formed.
With this balloon the problem is that absolutely air-tight connecting seams between the segments must be obtained. According to the state of the art the segments are interconnected using simplest technology by sewing with threads in single or multiple seams. This solution, however does not permit obtaining sufficiently airtight connecting zones, causing the balloons produced in this manner do deflate and to tend to collapse over time, which forces the designer to provide a pump using which the inside pressure in the balloon is maintained by pumping fresh air into the balloon.
Numerous documents in the patent literature concern inflatable balloons for illumination purposes. Here the French patent FR 717535 of 1931 is to be cited, merely in the sense of an example, which shows an inflatable balloon on which it was tried to find a solution of the problem of sealing the closure of the inlet sleeve for the electric cable airtight. Further examples of inflatable balloons none of which, however, shows the segmental layout, which characterizes the present invention, are contained in the patent documents U.S. Pat. No. 4,463,513, U.S. Pat. No. 3,610,916, U.S. Pat. No. 4,704,934 or DE 3015962.
From the patent literature concerning balloons inflatable with air—or with a lighter-than-air gas—and equipped with an internal light source, as well as the manufacture thereof, no insight is gained concerning the joining of the segments forming the spherical balloon, except the technology of sewing the seams with thread along the segment rims. This system, however, cannot ensure the required tightness of the essentially spherical body forming the balloon, and thus special measures are to be taken in order to maintain the pressure constant inside the balloon.